MEDIUM: protocol: sockpair protocol
This protocol is based on the uxst one, but it uses socketpair and FD
passing insteads of a connect()/accept().
The "sockpair@" prefix has been implemented for both bind and server
keywords.
When HAProxy wants to connect through a sockpair@, it creates 2 new
sockets using the socketpair() syscall and pass one of the socket
through the FD specified on the server line.
On the bind side, haproxy will receive the FD, and will use it like it
was the FD of an accept() syscall.
This protocol was designed for internal communication within HAProxy
between the master and the workers, but it's possible to use it
externaly with a wrapper and pass the FD through environment variabls.
diff --git a/include/proto/proto_sockpair.h b/include/proto/proto_sockpair.h
new file mode 100644
index 0000000..4692461
--- /dev/null
+++ b/include/proto/proto_sockpair.h
@@ -0,0 +1,28 @@
+/*
+ * Socket Pair protocol layer (sockpair)
+ *
+ * Copyright HAProxy Technologies - William Lallemand <wlallemand@haproxy.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef _PROTO_PROTO_SOCKPAIR_H
+# define _PROTO_PROTO_SOCKPAIR_H
+
+int recv_fd_uxst(int sock);
+int send_fd_uxst(int fd, int send_fd);
+
+#endif /* _PROTO_PROTO_SOCKPAIR_H */
+